fix(android): Add SSL error handling for Android WebView (#1450 by @thephpjedi)

Based on PR #668. Fixes #259.

android/src/main/java/com/reactnativecommunity/webview/RNCWebViewManager.java

@@ -10,6 +10,7 @@ import android.content.pm.PackageManager;
 import android.graphics.Bitmap;
 import android.graphics.Color;
 import android.Manifest;
+import android.net.http.SslError;
 import android.net.Uri;
 import android.os.Build;
 import android.os.Environment;
@@ -26,6 +27,7 @@ import android.webkit.CookieManager;
 import android.webkit.DownloadListener;
 import android.webkit.GeolocationPermissions;
 import android.webkit.JavascriptInterface;
+import android.webkit.SslErrorHandler;
 import android.webkit.PermissionRequest;
 import android.webkit.URLUtil;
 import android.webkit.ValueCallback;
@@ -797,6 +799,50 @@ public class RNCWebViewManager extends SimpleViewManager<WebView> {
       return this.shouldOverrideUrlLoading(view, url);
     }
 
+    @Override
+    public void onReceivedSslError(final WebView webView, final SslErrorHandler handler, final SslError error) {
+        handler.cancel();
+
+        int code = error.getPrimaryError();
+        String failingUrl = error.getUrl();
+        String description = "";
+        String descriptionPrefix = "SSL error: ";
+
+        // https://developer.android.com/reference/android/net/http/SslError.html
+        switch (code) {
+          case SslError.SSL_DATE_INVALID:
+            description = "The date of the certificate is invalid";
+            break;
+          case SslError.SSL_EXPIRED:
+            description = "The certificate has expired";
+            break;
+          case SslError.SSL_IDMISMATCH:
+            description = "Hostname mismatch";
+            break;
+          case SslError.SSL_INVALID:
+            description = "A generic error occurred";
+            break;
+          case SslError.SSL_NOTYETVALID:
+            description = "The certificate is not yet valid";
+            break;
+          case SslError.SSL_UNTRUSTED:
+            description = "The certificate authority is not trusted";
+            break;
+          default: 
+            description = "Unknown SSL Error";
+            break;
+        }
+        
+        description = descriptionPrefix + description;
+
+        this.onReceivedError(
+          webView,
+          code,
+          description,
+          failingUrl
+        );
+    }
+    
     @Override
     public void onReceivedError(
       WebView webView,